[lammps-users] Dihedral problem with polymer-CNT simulation

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1

Hello,

I am Syamal Tallury from Polymer Science department at NCSU. I have been trying to set up polymer-carbon nanotube systems to run on lammps molecular dynamics package with PCFF (class 2) forcefield. I have tried several times to get all the parameters right for the dihedral coefficients, bond-bond, oop etc. cross terms. After I get everything right, I find that the simulation runs for a few steps and starts giving out ‘nan’ for all atom coordinates and statistics.I will be happy provide the input files in case you want me to.
Please inform me if anyone else has faced this problem and if so, how it could be solved.

Thank you.

2

I would take a configuration with your ff assignments and
verify that you get the same energy/forces as with some
other code, assuming you are porting a model.

Steve